Carbon black

Abstract

Carbon black characterized by a STSA surface of between 20 and 180 m2/g, a 24M4-DBP absorption of between 40 and 140 ml/100 g, a specific BET surface of between 20 and 250 m2/g, a content of 0.01 to 20 wt. % of silicon, referred to its overall weight, and a tan delta0/tan delta60 ratio greater than 3.37-0.0068 STSA is produced by mixing silicon-containing compounds with the carbon black raw materials in the oxidative pyrolysis of the carbon black raw materials and optionally using carbon black oil as fuel. The carbon black can be used as a filler in rubber mixtures, preferably for tires.

What is claimed is:  
     
       1. A carbon black with a STSA surface of between 20 and 180 m 2 /g, a 24M4-DBP absorption of between 40 and 140 ml/100 g and a specific BET surface of between 20 and 250 m 2 /g and a content of 0.01 to 20 wt. % of silicon, referred to its overall weight, 
       wherein in rubber mixtures said carbon black has a tan δ 0 /tan δ 60  ratio greater than 3.37−0.0068 STSA, and  
       wherein said carbon black is produced by a seed-induced carbon black formation.  
     
     
       2. A carbon black according to  claim 1 , further comprising 0.01 to 1 wt. % of nitrogen, in addition to said silicon. 
     
     
       3. A process for producing a carbon black according to  claim 1 , comprising: 
       formation of carbon black seeds by combustion of carbon black oil, oil, a mixture of oil and natural gas or natural gas alone as fuels, and  
       oxidative pyrolysis of carbon-containing carbon black raw material in a carbon black reactor,  
       wherein silicon-containing compound is mixed into the carbon-containing carbon black raw material.  
     
     
       4. A process for producing a carbon black according to  claim 3  by oxidative pyrolysis of the carbon-containing carbon black raw material, comprising: 
       spraying silicon-containing compounds into at least one reaction chamber of the carbon black reactor.  
     
     
       5. A process according to  claim 3 , 
       wherein said silicon-containing compound is at least one organosilicon compound selected from the group consisting of organosilanes, organochloro-silanes, silicic acid esters, siloxanes and silazanes.  
     
     
       6. A process according to  claim 3 , comprising: 
       bringing the carbon black raw material into direct contact with said carbon black seeds.  
     
     
       7. A process according to  claim 6 , wherein the fuel comprises carbon black oil, and the process further comprises: 
       varying silicon distribution in the carbon black by varying mixing of the silicon-containing compound in the carbon black oil.  
     
     
       8. A method of using the carbon black according to  claim 1 , comprising: 
       adding the carbon black as a reinforcing carbon black in rubber mixtures for making tires, wherein said tires have reduced rolling resistance and improved wet skidding behavior.